1. Field of the Invention
The present invention relates to a spindle motor and a hard disk drive including the same.
2. Description of the Related Art
A so-called fixed shaft-type spindle motor in which a shaft having excellent vibration properties is fixed to a case of a hard disk driving device is frequently used in an information recording/reproducing device of a hard disk driving device for a server.
That is, the shaft is fixed to the spindle motor mounted on the hard disk driving device for the server, in order to prevent information recorded on a disk from being corrupted and not being able to be read or to prevent information from not being able to be written to a disk when an amplitude of a rotor is increased due to external vibrations.
As such, in the case in which a fixed type shaft is installed, a thrust member is provided in upper and lower portions of the shaft.
However, in the case in which the shaft is fixed to the lower thrust member and the lower thrust member is fixed to a base, the shaft needs to be firmly fixed, so the lower thrust member is thicker to be fixed to an outer circumferential surface of the shaft by as press-fitting, bonding, and slide-coupling or the like.
Meanwhile, recently, as hard disk drives have been thinned, the spindle motor used therein has also been thinned. However, as described above, in the case in which the lower thrust member is thick, since thinness of the spindle motor is prevented and a length of a bearing span is unavoidably shortened, whereby the performance of the motor may be deteriorated.
Patent Document 1 relates to a fixed shaft-type spindle motor and includes upper and lower thrust members 230 and 220. As illustrated in FIG. 4, in the case of a structure in which a shaft 210 is fixed to the thrust member 220, the shaft 210 may be firmly fixed in the case that the lower thrust member 220 is relatively thick.